Toad Data Modeler 6.4 - User Guide

Create Attributes

You can create attributes in:

• Entity right-click menu on Workspace
• Entity Properties dialog
• Attribute Properties dialog
• Model Explorer

To create an attribute on the Workspace

Right-click an entity on the Workspace and select Add | Attribute. The Attribute Properties dialog opens.

Note: Select the Primary Key (Unique) checkbox to set the attribute as PK or unique attribute.

To create an attribute in the Entity Properties form

1. Double-click an entity on Workspace.
2. In the Entity Properties form, switch to the Attributes tab and click Add.
   
   

Entity Properties attribute columns

Column/Option	Description
Key	Graphical representation of keys of a particular attribute
Caption	Logical attribute name
Name	Physical attribute name
Data Type	Data Type of an attribute TIP: You can set a default data type for newly created attributes. See Settings Menu | Options | Physical Model | *database platform and version* | Default Data Type combo-box. (The selected data type will be also applied to Dictionary Types and Domains.)
p1	Parameter 1. Only some of the available data types have this parameter. Defines properties of the selected data type, e.g. length in case of the Char data type.
p2	Parameter 2. Only some of the available data types have two parameters. E.g. the Decimal data type has two parameters, which define precision and scale.
Not Null	When checked, the attribute cannot be empty.
Comments	Comments or descriptions related to the attribute
Status	Shows status of attributes in grid. Status of Items in Grids

Buttons:

- opens the Application Variables form

Smaller Add button- adds new attributes quickly, just enter attribute name and then click Add.

Bigger Add button - adds an attribute

Edit - opens Attribute Properties of the selected entity

Delete - deletes the selected attribute

- moves the selected attribute up or down in the list

To create another attribute in the Attribute Properties form

Click OK+Add.

To create an attribute in Model Explorer

Unfold the Entities folder | Unfold the specific entity folder | Right-click the Attributes folder | Add Attribute.

Create Primary Key

An entity can have a primary key and many alternate keys. The keys are stored in the Keys tab in the Entity Properties form.

To create a key

• Right-click an entity on the Workspace and select Add | Key. The Key Properties dialog opens.

To create a PK (unique) attribute

1. Right-click an entity on the Workspace and select Add | Attribute. The Attribute Properties dialog opens.
2. On tab General, select the Primary Key (Unique) checkbox.

To assign an attribute to key

• In the Entity Properties dialog, Attributes tab, double-click the empty space in the Key column next to the selected attribute.

or

• In the Key Properties dialog | Attributes tab.

NotNull Property for PK and AK Attributes

Toad Data Modeler allows you to check/uncheck the NotNull property for PK and AK attributes.This is possible only if the Allow Null Attributes in Keys checkbox is selected (unchecked by default).

To select this checkbox

Select Settings | Options | Physical Model and select the checkbox.

If this checkbox is not selected, Toad Data Modeler doesn’t allow you to uncheck the NotNull checkbox in key attributes.

The availability of this option differs by database:

If the Allow Null Attributes in Keys checkbox is selected:

• When you assign an attribute to a key (PK, AK), the Not Null checkbox of the attribute will be checked. (But you are able to uncheck it)
• During propagation of the key via the identifying relationship, the Not Null property in child attribute is inherited from the parent attribute. The only exception is when a database doesn't support Null value in primary key, which would be created via the propagation.
• During Model Conversion, different settings of the Not Null property and its support in different databases are taken into consideration.
• For databases that support Null value in child attribute, the Mandatory Parent checkbox is selected in the Relationship Properties dialog and should behave coherently to Null value in child attribute as well as it behaves for non-identifying relationships.
• For databases that support Null value in child attribute, the settings of the Synchronize NotNull with Mandatory Parent option work the same way for PFK as for FK.

See Synchronization of NotNull and Mandatory Parent for more information.

Create Relationship

1. Select a relationship type - click the appropriate relationship icon on the toolbar:

 Identifying relationship (also CTRL+R)

 Non-identifying relationship

   M:N relationship

2. Move your mouse cursor over the work area. (The cursor changes its appearance.)
3. Click the first entity (parent) and then the target entity (child).

To create self-relationship for non-identifying relationship

1. Click the Non-identifying relationship icon on the toolbar .
2. Move your mouse cursor over the work area.
3. Double-click the selected entity on the Workspace.

To add multiple relationships

1. Press SHIFT and click the Relationship icon. See the blue frame in the icon now.
2. Create as many relationships in you model as you need.
3. Right-click the work area (or click the Relationship icon again) to turn this function off.

Notation and Cardinality

IE Notation

Cardinality

One-to-many relationship is represented by this symbol:

One-to-one relationship is represented by this symbol:

Parent: mandatory Child: mandatory

Parent: mandatory Child: optional

Parent: optional Child: mandatory

Parent: optional Child: optional

IDF1X Notation

Cardinality

,  ,   zero, one or more

one or more

zero or one

Parent: mandatory Child: mandatory

Parent: mandatory Child: optional

Parent: optional Child: mandatory

Parent: optional Child: optional

See Synchronization of Not Null and Mandatory Parent for more information.

Relationship Types

Identifying Relationship

Non-identifying Relationship

Non-identifying Self-relationship

M:N Relationship